SagaContext class

Manages saga context. Context is basically a key/value dictionary stored in objects member of class. Middleware creates and manages context by instantiating SagaContext.

Use Options to pass initial context to middleware. In most cases no need to instantiate this class manually. Context can be read and modified by effects GetContext and SetContext

 // create middleware and pass options
 var sagaMiddleware = createSagaMiddleware(
   //initiate context with options
   Options(context: <dynamic, dynamic>{#a: 1}),
 );

 // create store and apply middleware
 final store = Store<int>(
   counterReducer,
   initialState: 0,
   middleware: [applyMiddleware(sagaMiddleware)],
 );

 // attach store
 sagaMiddleware.setStore(store);

 // run saga
 sagaMiddleware.run(() sync* {
  var result = Result<dynamic>();

  //read context
  yield GetContext(#a, result: result);

  //set context
  yield SetContext(<dynamic, dynamic>{#b: 2});
 });

Constructors

SagaContext([Map? objects])

Creates an instance of a SagaContext.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

keys → List

Returns context items keys

no setter

objects ↔ Map

Context values stored at objects. It is a map dictionary with key/value pairs.

getter/setter pair

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

add(dynamic name, dynamic object) → void

Adds new item named name to the context with the value object if it already exits then set object as new value

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

remove(dynamic name) → void

Removes context item with name

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

operator [](dynamic name) → dynamic

Indexed get property to access context values